In Nixon v. Fitzgerald¹, the Supreme Court wrote “While the separation of powers doctrine does not bar every exercise of jurisdiction over the President, a court, before exercising jurisdiction, must balance the constitutional weight of the interest to be served against the dangers of intrusion on the authority and functions of the Executive Branch.”
The current court cited that thusly in Trump v United States²:
"At a minimum, the President must be immune from prosecution for an official act unless the Government can show that applying a criminal prohibition to that act would pose no ‘dangers of intrusion on the authority and functions of the Executive Branch’.”
Fitzgerald described a balancing test between the public interest and the dangers of intrusion. Trump truncated the quote to turn it into a prohibition.
This Court is purely outcome-driven. In my mind, that makes it illegitimate. We might try returning to the original Constitutional order, in which it was recognized that all three branches of the government had a role in Constitutional interpretation and that differences would be settled through the “checks and balances” mechanism of each group jealously guarding its (separate) power. The power grab of Marbury v. Madison³ has not served the people well.
It’s fair to point out that the Founders’ dislike of political parties and consequent assumption that they would therefore not exist held for between zero and seven years⁴, and that it was party allegiance across government branches that put the lie to Madison’s theoretical concept of governance. So we have more work to do than break the stranglehold of life-tenured, unelected, barely-doing-the-work-of-maintaining-the-pretense partisan politicians over the legal system.
Fortunately, unlike Madison – who was inventing a whole new thing – we have many examples of successful multi-party democracies that work better⁵ as well as ones that don’t⁶. It should be possible to be distill the various systems down and implement a gradual transition to a new constitutional order. (Seems like step 1 needs to be a constitutional amendment making constitutional amendments both easier and work better. Details are left as an exercise for the reader.)
³ https://en.wikipedia.org/wiki/Marbury_v._Madison
⁴ https://en.wikipedia.org/wiki/First_Party_System#Newspapers_as_party_weapons
⁵ I get vague good vibes from Ireland and Germany, but I'm no expert.
⁶ Israel seems widely considered a mess. Mexico and Japan's systems seem to have flaws that incline them to be one-party multiparty democracies. The UK shows that first-past-the-post single-representative constituencies push countries into being effectively two-party states, so that's another thing to fix.